“Sen. Reed is trying to get as many supporters as he can from both sides of the aisle,” said Chip Unruh, Reed’s spokesman. “We are cautiously optimistic that enough members will do the right thing for their constituents and our economy and pass the bipartisan 3-month Reed-Heller fix.”

A Democratic leadership aide said Heller’s office “is optimistic he will get a few other folks to vote for cloture.”

President Obama interrupted his vacation to call Reed and Heller from Hawaii to encourage them.

Democrats need at least 5 Republican votes to advance a motion to proceed to the bill. Then Republicans could have a chance to amend it before voting to overcome another 60-vote hurdle to set up final passage.

Senate passage is a high political priority for Heller, whose home state is tied with Rhode Island for having the highest unemployment rate in the nation at 9 percent, according to the Bureau of Labor Statistics.

So far, however, no other Senate Republican has announced support for the aid package.

Rep. Dave Camp (R-Mich.), the chairman of the Ways and Means Committee, thinks legislation designed to speed the economy should be Congress’s primary focus.

“Despite a dozen extensions, academic research suggests the program has actually hurt, rather than helped, the job creation that the unemployed need most,” said Michelle Dimarob, a spokeswoman for the Ways and Means panel.

“It is time to focus on policies that will actually lead to real economic opportunities for families who are trying to get back on their feet and back into the workplace,” she said.

Critics say the GOP approach ignores the plight of families who depend on federal assistance to live day-to-day.

“There are eleven million unemployed. You’re not going to create enough jobs for all those people and they need to live,” said Eisenbrey.

Reid has taken a strong stance against paying for unemployment benefits, which he views as an emergency expenditure.

He has voiced interest in reforming the program, although not in the same ways that Republicans have proposed.

He told the Las Vegas Sun last month that he would like to lower the unemployment rate thresholds that determine the length of benefits for individual states. Only states with 9-percent unemployment rates are eligible for 73 weeks of benefits, the maximum length of combined state and federal assistance.

“Hopefully, we can bring that number down,” he told his home-state paper.

Getting Senate Republicans to vote to proceed to the unemployment package will be easier than persuading them to end debate and set up a final measure if Democrats continue to insist that its cost not be offset.

“I think it’s going to be a very close call in the Senate but we’re optimistic they’ll eventually do the right thing,” said Judy Conti, federal advocacy coordinator for the National Employment Project.

“I will not vote to bring this legislation to the floor unless senators have an opportunity to debate and vote on the many good ideas for helping unemployed Americans find a job," said Alexander, who has been known to reach across the aisle to work with Democrats.

"Unfortunately, the Senate appears to be starting the new year just like the old one ended, with the Democratic leader bypassing committee consideration and cutting off all amendments and debate on an important issue.”

“We will come back at this issue,” said Schumer, who also repeated his assertion from ABC’s “This Week” that it was “insulting” for Republicans to say that extended jobless insurance acted as a disincentive for people to search for jobs.

“This is an issue that’s always had broad, bipartisan support,” Shaheen said on the conference call. “So it’s surprising that there’s not that kind of bipartisan support, or at least it’s not clear there will be, to continue this.”

The Senate debate will play out over the next week but time is limited because Congress must pass legislation by Jan. 15 to keep the government funded through the rest of the fiscal year.

The Senate will vote on the motion to proceed to Reed-Heller shortly after 5:30 p.m. Monday, after the Senate votes to confirm Janet Yellen to serve as the next head of the Federal Reserve.

Mike Lillis and Bernie Becker contributed to this report, which was updated at 10:17 p.m.